Chair base



Nov. 17, 1959 w. H. MCKINLEY CHAIR BASE 5 Sheets-Sheet 1 Filed April 2,1958 INVENTOR WILLIAM H.MKINLEY W. H. M KINLEY Nov. 17, 1959 CHAIR BASEFiled April 2, 195a 5 Sheets-Sheet 2 INVENTOR WILLIAM .M KINLEY IATTORNEY Nov. 17, 1959 w. H. MCKINLEY 2,913,208

CHAIR BASE Filed April 2, 195a 5 Sheets-Sheet :5

WILLIAM HMCKINLEY BY M ATTORNEY INVENTOR Nov. 17, 1959 w. H. MCKINLEYCHAIR BASE 5 Sheets-Sheet 4 Filed April 2, l958= I I INVENTOR .WILLIAMH.M KINLEY Nov. 17', 1959 w. H. MCKINLEYI CHAIR BASE 5 Sheets-Sheet 5Filed April 2, 1958 I INVENTOR. WILLIAM H. M KINLEY United States PatentC) CHAIR BASE William H. McKinley, Youngstown, Ohio, assignor to TheGeneral Fireproofing Company, Youngstown, Ohio, a corporation of OhioApplication April 2, 1958, Serial No. 725,821

6 Claims. (Cl. 248-194) This invention relates to an advancedimprovement in bases for swivel chairs.

Heretofore, bases for swivel ofiice chairs have been made solid orintegral from either one-piece steel or aluminum stampings, and in somecases the bases have been made of cast metal. Also, it is known in theart to provide a pressed metal chair base with sculf plates, namely,plates superimposed on the outer ends of the legs to assume the wear andabrasion of the chair-users shoes.

However, with the advent of modern furniture design, and the current useof anodized aluminum in many widely diiferent colors, it becomesdesirable to provide a fabricated chair including a substructure and ananodized aluminum cap or shell.

In other words, because steel and aluminum require separate anddifferent methods of manufacture and treatment for ornamentation, it isdesirable to have a fabricated chair base wherein the substructure maybe built up out of pressed metal parts, or a cast structure, both ofwhich will be covered or capped with a shell made from a relatively thinsheet of aluminum, either in its natural finish or in color.

Accordingly, the present invention has primarily in view a compositechair base including a substructure of adequate strength and an aluminumcap or shell, making it possible to practically provide a wide range ofnovel, ornamental eflfects while providing a base of the required weightand stability.

Another object is to provide a fabricated steel or cast substructure anda shell both of which lend themselves to conventional manufacturingprocedures and convenient methods of assembly to maintain costs withinreasonable limits.

A further object of the invention is to provide a simple and practicalconstruction which is strong and sturdy and adequately able to withstandthe severe use to which a swivel chair base is normally subjected.

With the above and other objects in view, which will appear as thenature of the invention is better understood, the invention consists inthe novel construction, combination, and arrangement of partshereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown in theaccompanying drawings, in which:

Fig. l is a top plan view of a composite chair base made in accordancewith the present invention.

Fig. 2 is a side elevation, partly in section of the construction shownin Figure 1.

Fig. 3 is a vertical cross-sectional view taken on the line 33 of Fig.1.

Fig. 4 is a vertical sectional View taken on the line 4-4 of Fig. 2.

Fig. 5 is a vertical sectional view taken on the line 55 of Fig. 2.

Fig. 6 is a vertical sectional view taken on the line 66 of Fig. 2.

Fig. 7 is an enlarged detail,.exploded, perspective view 2,913,208 C fPatented Nov. 17, 1959 of the stamped lower substructure of the base inits fabricated form.

Fig. 7a is a detail, perspective view of the upper spider.

Fig. 7b is a partial perspective view of the shell which overlies thespider and the lower leg forming structure.

Fig. 8 is a detail side elevation, partly in section of a castsubstructure.

Fig. 9 is a detail top plan view of the hub portion of the castsubstructure of Fig. 8.

Fig. 10 is a vertical section taken on the line Ill-10 of Fig. 9.

Fig. 11 is a detail vertical section taken on the line 11-11 of Fig. 8.

Similar reference numerals designate corresponding parts throughout theseveral figures of the drawing.

The chair base as a whole, preferably has four legs radiating from thezone of a central hub and, as will be seen from the drawings, generallyincludes, in Figs. 1-717, a skeleton steel fabricated substructure A,and in Figs. 8-10, a cast substructure A, each respectively covered andconcealed by and interlocked with a one-piece shell or cap B and B.

Referring first to the substructure A of Figs. l.7a, it will be observedthat the same includes the lower half A of the central hub portionhaving the bottom end of a tubular sleeve '1 fitted thereto, said sleeveintended to receive the bearing of the adjusting screw of the chairiron, not shown. This sleeve 1 constitutes the primary assembly pointfor the substructure, including the stamping forming the lower portionof the similar legs of the base and an upper central spider S. i

A description of the formation of one skeleton leg will suffice for theothers. i

Each leg member includes a primary lower section 2 having its inner endformed on an arc (Figs. 1 and 7) and also deformed medially downward at2i: while its central portion is provided with an inner upstandingflange 3 which fits within the lower end of the tubular sleeve 1 and iswelded thereto. i

As will be observed more particularly from Figs. 4 and 7, the lowersection 2 is of generally channel cross-section and the side walls 4thereof have their upper portions 4*- inclined inwardly toward eachother. Each of the legs are medially provided with longitudinalshoulders 5 which, as will later appear, assist in locking and holdingthe shell B in place. These shoulders continue about the lower half A ofthe central hub and the side walls 4 taper away from the said centralhub portion of the base toward the outer ends of the legs as shown inFig. 2.

Above the shoulders 5 the inturned portions 4 of the side walls 4 ofeach lower leg section are intended to telescopically receivetherewithin the downturned flange portions 6 of the arms 7 of thereinforcing spider S. These arms are of substantially inverted U-shapedcross section, as will be apparent from Figs. 3, 4 and 7a. The upperwall of the spider 7 is provided with a central, downturned collar 8which fits into the upperend of the tubular sleeve 1 to be securedthereto by conventional means. a r

It will, of course, be understood that the walls 4 and flanges 6 of themembers 2 and 7 are welded together about the tubular sleeve 1 toprovide a solid skeletal substructure.

As will be seen from Figs. 2, 7 and 7a, for example,

the outer ends 611 of the arms of the spider S are not the 3 the walls 4on the leg2 (Figs. 2 and 7). As will be seen from these figures, theouter portion of each toe piece has a horizontal bottom wall 11,downwardly offset as at 12 and providing a ground including an openingfor receiving the caster shank tube 13 whose flanged end 14 ispreferably welded in place. Also the bottom .wall 11 is provided with akeeper 15 to receive and lock the shell B in place as will later appear.In addition, the outer edge of the wall 11 is formed with a struck uptang 16. This tang is intended to fit within the front Wall 17 of thehood 18 of the toe assembly including:

the side walls 19; a substantially flat top wall 20 provided with a weldaccess slot 21; and the rearwardly extending inverted channel portion22, the latter intended to fit within and between the walls 4, 4 of theleg member 2.'

When the caster socket 13 is fitted in the opening in the bottom wall11, it may be welded in place at its top through the slot 21.

It will, of course, be understood that the side wall portions 10 of thebottom of the toe piece, when fitted within the mating portion of thebottom wall 2 of the primary leg member and between the walls 4, 4 arewelded together to make a strong connection therebetween. Also, the hoodportion 19 of the upper portion of the toe assembly is fitted about thebottom wall 11 of the toe piece and its channel shaped portion 22fitting within the walls 4, 4 is secured in place by appropriate welds.

After the legs having the construction set forth are assembled about thesleeve 1, the aluminum shell B is put in place. This shell (Fig. 7b)preferably comprises a single piece of stamped aluminum having anannular central portion 23 provided with an opening 24 for registeringwith the sleeve 1. The shell also has radial arms C of inverted U-shapedcross section and whose downturned side walls 25 are provided withinturned flanges 26 which are coextensive with and engage behind theshoulders 5 of the substructure.

When the outer ends or tip portions of the arms of the shell B aresuperimposed in registry with the legs of the substructure A, it will beseen that the skeletal form of the base is preferably substantiallyconcealed o1 masked by the shell, only a small portion of the side walls4 projecting below the flanges 25 in the zone of the central hub portionbeing visible.

The outer ends or tip portions 27 of the shell B are provided with thetongues 28 which are intended to have their end portions turned back andinto the keeper 15, here in the form of a slot, in the bottom wall 11 ofthe toe assembly.

It will now be seen that the substructure A is fabricated of a strongmetal such as steel and forms the support for the outer, upper shell B.When the keeper flanges 26 of the substantially inverted channel shapedsides 25 of the shell are interlocked with the shoulders 5 on the sidesof the leg 2, and the tongum 28 are in keepers 15, the entire compositearrangement will be securely united for use.

Aside from the structural features which give strength to the entirechair base, the flexibility of combining aluminum and steel finished indifferent colors is made feasible and possible from a productionstandpoint.

While in its preferred form, the substructure A is pref erably assembledof pressed steel parts interlocked and welded, nevertheless, it ispossible to make the sub structure A in cast form, as shown,for'example, in Figs. 9-11.

Referring first to Fig. 9, it will be seen that the hub 30 may be madeof cast material to receive the tubular sleeve 31 (Fig. 9) and the sidewalls of the legs 32 are provided with ribs 33 which present shoulders34 interlocking with the inturned flanges 35 of the shell B.

Referring to Figures 9, 10 and 11, it will be seen that the hub 30 andradial leg members 32 are cast in one integral piece, preferably ofaluminum alloy, although steel may be used for adding weight to theentire base to provide adequate balancev and stability for the entirechair. 1

The toe portions 36 of each leg 32 are provided with a caster shankreceiving socket 37 and the outer bottom portion of the toe is providedwith a keeper in the form of a notch or recess 38 for receiving thelocking tongue 39 at the tip end of the arms of the shell B. This shellfollows the same pattern as the shell B in the respect that it is ofinverted channel shape formation to include opposite side flanges 40provided with locking flanges 41 intended to engage with the shoulders34 on the base. The shell B, as will appear from Figure 10, has arelatively flat central portion 42 provided with an opening 43 forregistering with the bearing sleeve 31, and as each leg tapers outwardlyfrom the hub portion 30, the shell or mask B follows its general shapeand contour.

From the foregoing it will be seen that in both the fabricatedsubstructure A of Figures l-8 and the cast or integral substructure A ofFigures 9l0, the conditions are substantially the same with respect tothe shells B and B masking the upper portions of the legs.

The shells are preferably made from stamped aluminum sheet material andmay be made in a color to contrast with the lower exposed portion of thelegs. For example, the base may be painted one color and the shell maybe made of anodized colored aluminum in a different color.

Also in both forms of construction the shell has a medial opening forregistering with the tubular sleeve or bore, as the case may be, toreceive the chair spindle, and in each instance the outer end of eachradial portion of the shell which overlies the related portion of thesubstructure is mechanically interlocked with the substructure as, forexample, by a tongue engaging in keeper element whether it is a slot ora tongue.

I claim:

1. A fabricated chair base, comprising, a skeletal substructureincluding radial U-shaped legs having sides each formed with alongitudinal shoulder, a spider having radial portions registering withand fitting within said legs, a shell having radial arm portions inmating superimposed relation to said radial portions of the spider andthe arm portions of the legs, said arm portions of the shell being ofinverted U-shaped cross section having inturned locking flanges at theirlower edge for telescopic interfitting engagement with said shoulders,the said looking flanges and shoulders preventing separation of theshell and substructure, a central tubular hub connecting the spider andlegs, toe members secured to the outer ends of the legs and having akeeper slot, and tongues formed on the ends of the arms of the shell forentering said slots in the legs.

2. A fabricated chair base comprising, in combination, a substructure,concealed when the base is in use, said substructure including, acentral hub portion and integral radial legs, a downwardly facingshoulder at opposite sides of each of said radial legs extendingcontinuously longitudinally from approximately the end of said legs toand about the central hub portion, and a one-piece shell including a hubportion registering with said central hub portion and integral radialarms of greater length than said legs, said last mentioned hub portionand arms being of substantially inverted U-shaped cross section to coverthe top and sides of the legs and having inturned flanges along theirbottom edges for interlocking engagement with the said shoulders on thehub and legs of the substructure to hold the latter and shell together.

3. A fabricated chair base, comprising, in combination, a substructureincluding, a central hub portion and integral radial legs of U-shapedcross-section, downwardly facing shoulders at opposite sides of each ofsaid radial legs extending continuously longitudinally from said hub toapproximately the end of the leg, a toe assembly including a toe-piecefitting into the open outer end of each radial leg, a canopy of invertedU-shaped cross-section secured to said toe-piece, and a one-piece shellincluding a hub portion and integral radial arms of greater length thansaid radial legs of the substructure, said arms being of substantiallyinverted U-shaped cross section to cover the top and sides of the legsand having inturned flanges along their bottom edges for interlockingengagement with the shoulders on the radial legs of the substructure tohold the latter and shell together.

4. A fabricated chair base, comprising, in combination, a substructureconcealed when the base is in use, including, a central hub portion andintegral radial legs of substantially U-shaped cross-section, a shoulderformed at opposite sides of each radial leg and extending continuouslylongitudinally along the lower portion thereof from around said hub toapproximately the outer end of said leg, a reinforcing spider ofinverted U-shaped cross-section and having a hub portion and shortradial legs for telescopically fitting downwardly within the chan nelportions of each radial leg of the substructure, and a shell comprisinga hub portion and integral radial arms for registering with andoverlying the legs of said substructure, each of said arms being ofinverted U-shaped cross section and having inturned flanges along theirbottom edges for interlocking engagement With the shoulders on the legsof the substructure to hold the latter and the shell together.

5. A fabricated chair base, comprising, in combination, a substructureincluding a central hub portion, integral radial legs of substantiallyU-shaped cross-section, shoulders on opposite sides of said leg portionsextending continuously throughout the length thereof from the hubtowards the ends, a toe assembly including toe pieces interfitted withthe related outer ends of the U-shaped legs of the substructure, and ahood-like canopy on said toe piece, a reinforcing spider including shortradial arms of inverted channel shape cross-section having their flangesfitting within the upturned portions of the radial arms of thesubstructure adjacent the hub portion thereof, and a masking shell forcompletely registering with and covering the hub portion, radial armsand toe assembly of the substructure, said shell comprising a hub andintegral radial arms each having de pending and inturned flanges forengaging with the shoulders of the substructure to interlock the shellWith the substructure.

6. A fabricated chair base, comprising, in combination, a substructureincluding a unitary central hub portion having radial floor engaginglegs, downwardly facing shoulders disposed medially of and extendinglongitudinally along each side of'each leg; and a superimposed matingunitary covering shell for said substructure comprising, a central hubportion registering with the central hub portion of said substructure,and arms including spaced side Walls embracing the legs and masking thetop and sides thereof, and inturned flanges along the terminal portionsof the side walls of said arms for engaging related shoulders on thelegs of the substructure to interlock the shell and substructuretogether.

References Cited in the file of this patent UNITED STATES PATENTS2,021,187 Laflerty Nov. 19, 1935 2,350,399 Jones June 6, 1944 2,455,131Masterson Nov. 30, 1948 2,587,886 Penchoen Mar. 4, 1952 2,686,647 FitchAug. 17, 1954 2,732,157 Hamilton Jan. 24, 1956 2,746,705 McKinley May22, 1956 2,780,431 Carlson Feb. 5, 1957 FOREIGN PATENTS 603,581 GreatBritain June 18, 1948

